Infinitely refillable syringe

ABSTRACT

An angiographic injector system includes a manifold and valve which selectively connects either a syringe pump or a low pressure system to a catheter which is inserted into a patient. The valve is normally biased to a state which connects the low pressure system to the catheter for pressure-monitoring, saline flushing, or aspirating functions. When an injection is to be made, the valve automatically switches so that the low pressure system is disconnected and not exposed to high pressure, while the syringe pump is connected through the manifold to the catheter.

This application is a continuation of U.S. Ser. No. 08/957,801, filed onOct. 24, 1997, now U.S. Pat. No. 6,221,045, which is acontinuation-in-part of U.S. Ser. No. 08/946,293, filed on Oct. 7, 1997,now U.S. Pat. No. 5,800,397, entitled Angiographic System with AutomaticHigh/Low Pressure Switching, which is a file wrapper continuationapplication of U.S. Ser. No. 08/426,148 filed on Apr. 20, 1995, nowabandoned, which applications are hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to angiography and more specifically, theinjector system used to inject a medical fluid such as radiographiccontrast material into living organisms.

BACKGROUND OF THE INVENTION

One of the major systems in the human body is the circulatory system.Components of the circulatory system include the heart, blood vessels,and blood, all of which are vital for the transportation of materialsbetween the external environment and the cells and tissues of the body.

The blood vessels are the network of passageways through which bloodtravels in a human or animal body. Specifically, the arteries carryoxygenated blood away from the left ventricle of the heart. The arteriesare arranged in progressively decreasing diameter and pressurecapability from the aorta, which carries the blood immediately out ofthe heart to other major arteries, to smaller arteries, to arterioles,and finally to capillaries, where exchange of nutrients and wasteproducts between the blood and the cells and tissues of the body occur.Generally, veins carry oxygen depleted blood back to the right atrium ofthe heart using a progressively increasing diameter network of venulesand veins.

Angiography is a procedure used in the diagnosis and treatment ofcardiovascular conditions including abnormalities or restrictions inblood vessels. During angiography, a radiographic image of the heart ora vascular structure is obtained by injecting a radiographic contrastmaterial through a catheter into a vein or artery. The injected contrastmaterial can pass to vascular structures in fluid communication with thevein or artery in which the injection is made. X-rays are passed throughthe region of the body in which the contrast material was injected. TheX-rays are absorbed by the contrast material, causing a radiographicoutline or image of the blood vessel containing the contrast material.The x-ray images of the blood vessels filled with contrast material areusually recorded onto film or videotape and are displayed on afluoroscope monitor.

Angiography provides an image of the cardiac or vascular structures inquestion. This image may be used solely for diagnostic purposes, or theimage may be used during a procedure such as angioplasty where a balloonis inserted into the vascular system and inflated to open a stenosiscaused by atherosclerotic plaque buildup.

Currently, during angiography, after a catheter is placed into a vein orartery (by direct insertion into the vessel or through a skin puncturesite), the angiographic catheter is connected to either a manual or anautomatic contrast injection mechanism.

A simple manual contrast injection system typically has a syringe and acatheter connection. The syringe includes a chamber with a plungertherein. Radiographic contrast material is suctioned into the chamber.Any air is removed by actuating the plunger while the catheterconnection is facing upward so that any air, which floats on theradiographic contrast material, is ejected from the chamber. Thecatheter connection is then attached to a catheter that is positioned ina vein or artery in the patient.

The plunger is manually actuated to eject the radiographic contrastmaterial from the chamber through the catheter, and into a vein orartery. The user of the manual contrast injection system may adjust therate and volume of injection by altering the manual actuation forceapplied to the plunger.

Often, more than one type of fluid injection is desired, such as asaline flush followed by the radiographic contrast material. One of themost common manual injection mechanisms used today includes a valvemechanism which controls which of the fluids will flow into the valvingmechanism and out to the catheter within the patient. The valvemechanism can contain a plurality of manual valves that the usermanually opens and closes to direct fluid flow to a particular fluidchannel. When the user aspirates or injects contrast fluid into or outof the chamber the fluid flows through the path of least resistancedirected by the position of the valves. By changing the valve positions,one or more other fluids may be injected.

Manual injection systems are typically hand actuated. This allows usercontrol over the quantity and pressure of the injection. However,generally, most manual systems can only inject the radiographic contrastmaterial at maximum pressure that can be applied by the human hand(i.e., 150 p.s.i.). Also. the quantity of radiographic contrast materialis typically limited to a maximum of about 12cc. Moreover, there are nosafety limits on these manual contrast injection systems which restrictor stop injections that are outside of predetermined parameters (such asrate or pressure) and there are no active sensors to detect air bubblesor other hazards.

Currently used motorized injection devices consist of a syringeconnected to a linear actuator. The linear actuator is connected to amotor, which is controlled electronically. The operator enters into theelectronic control a fixed volume of contrast material to be injected ata fixed rate of injection. Typically, the fixed rate of injectionconsists of a specified initial rate of flow increase and a final rateof injection until the entire volume of contrast material is injected.There is no interactive control between the operator and machine, exceptto start or stop the injection. Any change in flow rate must occur bystopping the machine and resetting the parameters.

The lack of ability to vary the rate of injection during injection canresult in suboptimal quality of angiographic studies. This is becausethe optimal flow rate of injections can vary considerably betweenpatients. In the cardiovascular system, the rate and volume of contrastinjection is dependent on the volume and flow rate within the chamber orblood vessel being injected. In many or most cases, these parameters arenot known precisely. Moreover, the optimal rate of injection can changerapidly, as the patient's condition changes in response to drugs,illness, or normal physiology. Consequently, the initial injection ofcontrast material may be insufficient in volume or flow rate to outlinea desired structure on an x-ray image, necessitating another injection.Conversely, an excessive flow rate might injure the chamber or bloodvessel being injected, cause the catheter to be displaced (from the jetof contrast material exiting the catheter tip), or lead to toxic effectsfrom contrast overdose (such as abnormal heart rhythm).

At present, the operator can choose between two systems for injectingcontrast material: a manual injection system which allows for avariable, operator interactive flow rate of limited flow rate and apreprogrammed motorized system without operator interactive feedback(other than the operator can start/stop the procedure). Accordingly,there is a need for improvement in the equipment and procedures used forperforming diagnostic imaging studies.

SUMMARY OF THE INVENTION

The present invention is an angiographic injection system which includesboth high pressure and low pressure systems. The high pressure systemincludes a motor driven injector pump which supplies radiographiccontrast material under high pressure to a catheter. The low pressuresystem includes, for example, a pressure transducer for measuring bloodpressure and a pump which is used to both for delivering saline solutionto the patient and for aspirating waste fluid. In the present invention,a manifold is connected to the syringe pump, the low pressure system,the catheter which is inserted into the patient. A valve associated withthe manifold is normally maintained in a first state which connects thelow pressure system to the catheter through the manifold. When pressurefrom the syringe pump reaches a predetermined level, the valve switchesto a second state which connects the syringe pump to the catheter, whiledisconnecting the low pressure system from the catheter.

It will be appreciated that while the invention is described withreference to an angiographic injector, the devices and methods disclosedherein are applicable for use in performing other diagnostic andinterventional procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a preferred embodiment of theangiographic injector system of the present invention.

FIGS. 2A-2G are diagrams illustrating operations of the system of FIG.1.

FIG. 3 is an electrical block diagram of the control system of theinjector system of FIG. 1.

FIG. 4 illustrates front panel controls and displays of a preferredembodiment of the injector system of the present invention.

FIGS. 5A and 5B are side and partial top perspective views of the remotecontrol of the system of FIG. 1.

FIG. 6 is a perspective view of a foot operated remote control.

FIGS. 7A-7D illustrate the operation of the inlet check valve andmanifold during contrast fill, air purge, and patient inject operations.

FIGS. 8A-8C illustrate operation of the inlet check valve in greaterdetail.

FIG. 9 is a perspective view illustrating a preferred embodiment of aportion of the angiographic injector system of the present invention.

FIG. 10 is a side view of one embodiment of the shell of a manifoldaccording to the invention.

FIG. 11 is a top view of the embodiment of the manifold shell of FIG.10.

FIG. 12 is a bottom view of the embodiment of the manifold shell ofFIGS. 10 and 11.

FIG. 13 is a longitudinal cross section view of one embodiment of amanifold assembly according to the invention.

FIG. 13A is a longitudinal cross section view of one end of the manifoldshell of FIG. 13.

FIGS. 14A-C are longitudinal cross section views which sequentiallyillustrate the interaction of an elastomeric wiper and the inner surfaceof a manifold shell as the wiper moves from its low pressure position toits high pressure position.

FIG. 15 is a transverse cross section view through line 15-15 of FIG.11.

FIG. 16 is a transverse cross section view through line 16-16 of FIG.12.

FIG. 17 is a diagrammatic illustration of a temporal position of amanifold plunger between the low pressure position and the high pressureposition.

FIG. 18 is a cross section view through line 18-18 of FIG. 11.

FIG. 19 is a longitudinal cross section view of one embodiment of amanifold shell according to the invention.

FIG. 19A is a longitudinal cross section view of the embodiment of FIG.19 with the plunger wipe view in cross section and at a differentposition within the manifold shell.

FIG. 20 is a perspective view of two different embodiments for aninjection material temperature control device according to theinvention.

FIG. 21 is a perspective view of embodiment of a remote controlaccording to the invention.

FIG. 22 is a side view of the embodiment of a remote control of FIG. 21.

FIG. 23 is a front view of the embodiment of a remote control of FIG.21.

FIG. 24 is a rear view of the embodiment of a remote control of FIG. 21.

FIG. 25 is a top view of the embodiment of a remote control of FIG. 21.

FIG. 26 is an exploded perspective view of an adjustable transducerholder according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A. Application SerialNo. 08/426,149

FIG. 1 shows angiographic injector system 10 for injecting radiographiccontrast material into a blood vessel under interactive physiciancontrol. System 10 includes main console 12, hand held remote control14, syringe holder 16, syringe body 18, syringe plunger 20, radiographicmaterial reservoir (bottle) 22, one-way valve 24, manifold 26, highpressure tube 28, catheter 30, patient medication port 32, three-waystop-cock 34, T-connector 36, pressure transducer 38, stop-cock 40,tubing 42, peristaltic pump 44, saline check valve 46, waste check valve48, saline bag 50, waste bag 52, and bag support rack 54.

Console 12 houses the electrical controls for system 10, together withthe motors which drive piston 20 and peristaltic pump 44. On the frontsurface of console 12, user interface 54 provides control switches 56and display 58 through which the user may enter control settings andmonitor the operational state of system 10.

Remote control 14 is connected to console 12 by cable 60 (although inother embodiments remote control 14 may be connected by a wirelessconnection such as an RF, infrared optic, or ultrasonic link). Remotecontrol 14 is, in the embodiment shown in FIG. 1, a hand-held controlwhich includes reset and saline push button switches 62 and 64,respectively, and flow rate control lever or trigger 66. By squeezingtrigger 66, the user can provide a command signal to console 12 toprovide a continuously variable injection rate.

Syringe holder 16 projects from the left hand side of console 12.Syringe holder 16 is preferably a clear material, and includes a halfcylindrical back shell 68, a half cylindrical front door 70 (which isshown in open position in FIG. 1), and reservoir holder 72.

Syringe 18 is a transparent or translucent plastic cylinder having itsopen end 74 connected to console 12. Closed end 76 of syringe 18contains two ports: upper port 78 and lower port 80.

Plunger 20 is movable within syringe body 18. Plunger 20 is connectedto, and driven by a motor located within console 12.

Radiographic contrast material reservoir 22 is connected through one-waycheck valve 24 to upper port 78. Radiographic contrast material is drawnfrom reservoir 22 through check valve 24 and upper port 78 into thepumping chamber defined by syringe body 18 and plunger 20. Check valve24 is preferably a weighted one-way valve which permits air to flow fromsyringe body 18 back into reservoir 22, but will not permit radiographiccontrast material to flow from syringe body 18 to reservoir 22. Thispermits automatic purging of air from the system, as will be describedin more detail later.

Lower port 80 of syringe body 18 is connected to manifold 26. Manifold26 includes a spring biased spool valve which normally connectstransducer/saline port 82 and patient port 84. When radiographiccontrast material is to be injected, the pressure of the radiographicmaterial causes the spool valve to change states so that lower port 80is connected to patient port 84.

High pressure tube 28 is a flexible tube which connects patient port 84to catheter 30. Three-way stop-cock 34 is located at the distal end oftube 28. Rotatable luer lock connector 86 is connected to stop-cock 34and mates with luer connector 88 at the proximal end of catheter 30.Stopcock 34 either blocks flow between tube 28 and catheter 30, permitsflow, or connects medication port 32 to catheter 30.

In addition to injecting radiographic material into a patient throughcatheter 30, system 10 also permits other related functions to beperformed. A device for delivering the patient medication (not shown inFIG. 1) may be connected to medication port 32 when medication is to bedelivered through catheter 30 to the patient.

When catheter 30 is in place in the patient, and an injection ofradiographic contrast material is not taking place, pressure transducer38 monitors the blood pressure through the column of fluid which extendsfrom catheter 30, tube 28, patient port 84, manifold 26,transducer/saline port 82, tubing 90, T-connector 36, and tubing 92.Transducer 38 has an associated stop-cock 40 which allows transducer 38to be exposed to atmospheric pressure during calibration and also allowsfor removal/expulsion of trapped air so the dome chamber of transducer38 can be flushed with saline.

Peristaltic pump 44 supplies saline solution from bag 50 through salinecheck valve 46, tubing 42, T-connector 36 and tubing 90 to saline port82. When peristaltic pump 44 is operating to supply saline solution, thesaline solution is supplied through manifold 26 to patient port 84 andthen through tube 28 to catheter 30.

Peristaltic pump 44 also operates in an opposite direction to draw fluidfrom catheter 30 and through tube 28, manifold 26, tubing 90,T-connector 36 and tubing 42 to waste check valve 48 and then into wastecollection bag 52.

In a preferred embodiment of the present invention, syringe body 18,manifold 26, tube 28, catheter 30, T-connector 36, tubing 42, checkvalves 46 and 48, bags 50 and .52, and tubing 90 and 92 are alldisposable items. They must be installed in system 10 each time anangiography procedure is to be performed with a new patient. Once system10 is set up with all the disposable items installed, door 70 is closed,and syringe body 18 filled with contrast material and purged of air, theuser (typically a physician) enters into system 10 the safety parametersthat will apply to the injection of radiographic contrast material.These safety parameters typically include the maximum amount ofradiographic contrast material to be injected during any one injection,the maximum flow rate of the injection, the maximum pressure developedwithin syringe body 18, and the maximum rise time or acceleration of theinjection. To actuate an injection of contrast material, the useroperates remote control 14 by squeezing trigger 66. Within the presetsafety parameters, system 10 causes the flow rate of the injection toincrease as the force or distance of travel of trigger 66 is increased.

Typically, the user will meter the amount and rate of contrast materialinjected based upon continuous observation of the contrast outflow intothe structure being injected using fluoroscopy or other imaging methods.System 10 allows the user to tailor the contrast injections to the needsof the patient, thereby maximizing the quality of the procedure,increasing the safety, and reducing the amount of contrast materialrequired to perform the fluoroscopic examination.

FIGS. 2A-2G are diagrams illustrating fluid flow paths during sevendifferent operations of system 10. Those operational are contrast fill(FIG. 2A), air purge (FIG. 2B), patient inject (FIG. 2C), patientpressure (FIG. 2D), saline flush (FIG. 2E), aspirate waste (FIG. 2F),and medicate patient (FIG. 2G).

The contrast fill operation illustrated in FIG. 2A involves the fillingof syringe body 18 with radiographic contrast material from reservoir(contrast media supply) 22. The contrast fill operation is performedduring initial set up of system 10, and may be repeated during operationof system 10 whenever syringe body 18 is running low on radiographiccontrast material.

During initial set up of system 10, plunger 20 is initially driven toits furthest forward position adjacent closed end 76 of syringe body 18.This will expel to the atmosphere the majority of the air which islocated within syringe body 18.

Plunger 20 is then retracted, which creates a vacuum within syringe body18 which draws contrast material from reservoir 22 through check valve24 in syringe body 18 through upper port 78.

The Contrast Fill operation typically will result in some air beingdrawn into or remaining within syringe body 18. It is important, ofcourse, to prevent air from being injected into the patient throughcatheter 30. That is the purpose of the Air Purge operation shown inFIG. 2B. Also, the location of two ports at different elevations allowsfor a greater amount of safety in preventing air bubbles in theinjection.

During the Air Purge operation, plunger 20 travels forward to expeltrapped air within syringe body 18. The air, being lighter than thecontrast material, gathers near the top of syringe body 18. As plunger20 moves forward, the air is expelled from syringe body 18 through upperport 78 and one-way valve 24. In the embodiment illustrated in FIG. 2B,one-way valve 24 is a weighted one-way valve which allows flow ofradiographic contrast material from reservoir 22 to upper port 78, butwill not allow radiographic contrast material to flow in the oppositedirection from upper port 78 to reservoir 22. Valve 24 will, however,allow air to flow from port 78 to reservoir 22. As soon as radiographiccontrast material begins flowing out of syringe body 18 through upperport 78 to valve 24, valve 24 closes to prevent any further flow towardreservoir 22.

Valve 24 can also, in alternative embodiments, can be a solenoidactuated or motor driven valve operated under control of the electriccircuitry within console 12. In either case, valve 24 is capable towithstanding the relatively high pressures to which it will be subjectedduring the inject operation. Preferably, valve 24 is capable ofwithstanding static fluid pressures up to about 1200 p.s.i.

FIG. 2C illustrates the Patient Inject operation. Plunger 20 travelsforward under the interactive control of the user, who is controllingtrigger 66 of remote control 14. The movement of Plunger 20 createshydraulic pressure to force contrast material out of syringe body 18through lower port 80 and through manifold 26 and high pressure tube 28into catheter 30. As shown in FIG. 2C, syringe lower port 80 and patientport 84 are connected for fluid flow during the patient injectoperation.

Manifold 26 contains a valve which controls the routing of fluidconnections between patient port 84 and either syringe bottom port 80 ortransducer/saline port 82. In one embodiment of the present invention,manifold 26 includes a spool valve which is spring biased so thatpatient port 84 is normally connected to transducer/saline port 82 (asillustrated in FIGS. 2A and 2B). When the pressure at syringe bottomport 80 builds with the movement of plunger 20 forward, the bias forceagainst the spool valve is overcome so that syringe bottom port 80 isconnected to patient port 84, and transducer/saline port 82 isdisconnected the valve within manifold 26 protects pressure transducer38 from being exposed to the high pressure generated by the patientinject operation.

The spool valve opens automatically during the patient inject operationin response to increase pressure exerted on it from the syringe lowerport 80. The spool valve closes and returns to its original positionallowing for connection of patient port 84 to transducer 38 when aslight vacuum is applied by retraction of plunger 20 at the end of eachPatient Inject operation

In an alternative embodiment, the valve within manifold 26 is anelectromechanical or motor driven valve which is actuated at appropriatetimes to connect either syringe lower port 80 or transducer/saline port82 to patient port 84. The actuator mechanism is controlled by console12. Once again in this alternative embodiment, the valve protectspressure transducer 38 from being exposed to high pressure.

FIG. 2D illustrates the Patient Pressure operation. System 10 allows forreading of the patient's blood pressure, which is monitored throughcatheter 30. Patient blood pressure can be monitored through the use ofpressure transducer 38 at any time except during the patient inject,saline flush, and waste aspirate operations. The pressure reading beingproduced by pressure transducer 38 may be normalized by manually openingstop-cock 40 and closing stop-cock 34 to expose pressure transducer 38to atmospheric pressure.

During the Saline Flush operation illustrated in. FIG. 2E, salinesolution is used to flush all of the internal lines, pressure transducerchamber 38, tube 28, and catheter 30. As shown in FIG. 2E, peristalticpump 44 is operating in a direction which causes saline solution to bedrawn from bag 50 through check valve 46 and through tubing 42 to salineport 82. Manifold 26 connects saline port 82 to patient port 84 so thatsaline solution is pumped out of patient port 84 and through tube 28 andcatheter 30.

During the Aspirate Waste operation, patient port 84 is again connectedto saline port 82. During this operation, peristaltic pump 44 isoperating in the opposite direction from its rotation during the salineflush operation. As a result, patient fluids are aspirated from patientport 84 to saline port 82 and then through tubing 42 and check valve 48into waste collection bag 52. Peristaltic pump 44 acts as a valvepinching/occluding tubing 42 and preventing back flow to/from saline andwaste containers 50 and 52 in conjunction with check valves 46 and 48.

With catheter 30 in place within the patient, it may be desirable tosupply patient medication. System 10 allows for that option by providingpatient medication port 32. As shown in FIG. 2G, when stop-cock 34 isopen, a medication source connected to port 32 will be connected topatient port 84, and thereby to catheter 30. During the medicate patientoperation, peristaltic pump 44 and plunger 20 are not moving.

FIG. 3 is an electrical block diagram of the control system whichcontrols the operation of angiographic injector system 10. Theelectrical control system includes digital computer 100, which receivesinput signals from remote control 14 and front panel controls 56 throughinterface 102, and provides signals to display 58 to display operationdata, alerts, status information and operator prompts.

Computer 100 controls the motion of plunger 20 through a motor drivecircuit which includes motor 104, motor amplifier 106, tachometer 108,potentiometer 110, a rectifier 112, pressure sensing load cell 114, andAID converter 160.

Motor amplifier 106 provides a Drive I signal to motor 104 in responseto Control Voltage, Fwd/Rev, and/Brake signals from computer 100 and aspeed feedback signal from tachometer 108 through rectifier 112. Theoutputs of tachometer 108 and potentiometer 110 are supplied to computer100 through AJD converter 116 as Speed Monitor and Position Monitorsignals. These allow computer 100 to check motor speed, motor direction,and position (volume is a calculated value).

Pressure sensor 114 senses motor current or plunger force in order tomeasure the pressure being applied to the radiographic contrast materialwithin syringe body 18. This Pressure Monitor Signal is supplied throughA/D converter 116 and interface 102 to computer 100.

Peristaltic pump 44 is driven under the control of computer 100 throughpump motor 120, motor driver 122 and optical encoder 124. Computer 100provides Saline (Forward) and Waste (Reverse) drive signals to motordriver 122 to operate pump motor 120 in a forward direction for salineflush and a reverse direction for waste aspiration. Optical encoder 124provides the Speed Direction Monitor signal to interface 102 whichindicates both the speed and the direction of rotation of pump motor120.

FIG. 3 illustrates an embodiment of the control system in which valvemotor 130 is used to actuate valves such as one-way valve 24 and thevalve within manifold 26. In this embodiment, computer 100 controlsvalve motor 130 through motor driver 132, and monitors position througha Position Monitor feedback signal from potentiometer 134. In thisparticular embodiment, valve motor 130 is a stepper motor.

Computer 100 monitors temperature of the contrast material based upon aTemp Monitor signal from temperature sensor 140. Temperature sensor 140is preferably positioned near syringe body 18. If the temperature beingsensed by temperature sensor 140 is too high, computer 100 will disableoperation motor 104 to discontinue patient injection. If the temperatureis too low, computer 100 provides a /Temp Enable drive signal to heaterdrive 150, which energizes heater 152. In one preferred embodiment,heater 152 is a resistive film heater which is positioned within syringeholder 116 adjacent to syringe body 18.

Computer 100 also receives feedback signals from contrast bottle sensor160, forward limit sensor 162, reverse limit sensor 164, syringe missingsensor 166, chamber open sensor 168, no contrast bubble detector 170,and air in line bubble detector 172.

Contrast bottle sensor 160 is a miniature switch located withinreservoir holder 72. The state of the Contrast Bottle Present signalfrom sensor 160 indicates whether a reservoir 22 is in position withinholder 72. If reservoir 22 is not present, computer 100 will disable thefill operation.

Forward limit and reverse limit sensors 162 sense the end limitpositions of plunger 20. When plunger 20 reaches its forward limitposition, no further forward movement of plunger 20 is permitted.Similarly, when reverse limit sensor 164 indicates that plunger 20 hasreached its reverse limit position, no further reverse movements arepermitted.

Syringe missing sensor 166 is a miniature switch or infraredemitter/detector which indicates when syringe body 18 is not in positionwithin syringe holder 16. If syringe body 18 is not in position, allmovement functions are disabled except that plunger 20 can move to itsreverse limit position (i.e., return to zero).

Chamber open sensor 168 is a miniature switch or infraredemitter/detector which senses when door 70 of syringe holder 16 is open.When the signal from sensor 168 indicates that door 70 is open, allmovement functions are disabled. Only when door 70 is closed and lockedmay any movement be allowed. When door 70 is indicated as closed andsensor 166 indicates the syringe body 18 is in position, other normalfunctions of the system 10 can proceed.

Bubble detector 170 is positioned between reservoir 22 and top port 78,and is preferably an infrared emitter/detector which senses air bubbles.If an air bubble is sensed in the flow path between reservoir 22 and topport 78 during a fill operation, the fill operation is disabled until anew reservoir is connected.

Bubble detector 172 is positioned to sense air bubbles in high pressureline 28. It is preferably an infrared emitter/detector type of bubbledetector. Any air bubble which is sensed in high pressure line 28results in the disabling of all fluid push out functions, whether thefluid is saline solution from peristaltic pump 44 or contrast materialfrom syringe body 18.

The control system of FIG. 3 also includes the capability to provide acontrol signal to x-ray equipment through relay 180 which is controlledby computer 100. In addition, computer 100 receives data from bloodpressure transducer 38 and from an electrocardiograph (ECG) system,which is separate from injector system 10. The Pressure and ECG signalsare received through signal conditioners and A/D converter 190, and aretransferred to computer 100. The ECG signal is used by computer 100 inone preferred embodiment, to synchronize operation of motor 104 (andthus the Patient Inject operation) with heart beats.

Blood flow to the heart occurs predominantly in diastole (when the heartis between contractions). Continuous injection of contrast materialresults in spillage of the contrast material into the aorta duringsystole (during contraction). By injecting primarily during diastole,contrast dosage can be reduced without impairing the completeness of thecontrast injection into the coronary artery.

In a preferred embodiment, the injection of radiographic contrastmaterial is synchronized to the coronary artery blood flow. The timeperiods of systole and diastole are determined using anelectrocardiographic (ECG) electrical signal, arterial blood pressurewaveform analysis, or other timing based on the heart rate. Bycontrolling speed of motor 104, speed and therefore movement of plunger20, the injection of contrast material is interrupted during the periodof systole, which reduces or stops contrast injection during this time.In combination with remote control 14, the operator can vary the rate ofcontrast injection into the coronary artery while computer 100automatically pulses the contrast injection to the cardiac cycle.

The inertial forces of the moving contrast material and expansion of thecontainers and tubing holding the contrast material and transmitting itto the patient can cause a phase lag between movement of plunger 20within syringe body 18 and movement of contrast material out of catheter30 into the patient. To adjust to the phase lag between the plunger 20movement and contrast expulsion into the patient, a variable time offsetcan be entered through control panel 54 such that the timing of thecardiac cycle can be offset by a selected time. Since the magnitude ofthe phase lag may be dependent on the frequency of the heart rate, analgorithm within computer 100 continuously and automatically adjusts themagnitude of the time offset, based on the instantaneous heart rateduring the injection of contrast material.

FIG. 4 shows one embodiment of control panel 54 which illustrates thefront panel control switches 56 and display 58 of one embodiment of thepresent invention. Front panel control switches 56 include SetUp/Fill/End switch 200, Purge switch 202, Aspirate switch 204, Salineswitch 206, Enable OK switch 208, Injection Volume Limit switches 210 aand 210 b, Injection Flow Rate Limit switches 212 a and 212 b, InjectionPressure Limit switches 214 a and 214 b, Rise Time switches 216 a and216 b OK switch 218, Injection Range Toggle switch 220, Large InjectionOK switch 222, and Stop switch 224.

Set Up/Fill/End switch 200 is a momentary push button switch. When it isfirst activated, the user will be notified to place syringe 18 insyringe holder 16. When syringe 18 has been placed in syringe holder 16(which is indicated to computer 100 by sensor 166), the user will beinstructed to close and lock the chamber (i.e., to close door 70).Plunger 20 is moved to its full forward position expelling all airwithin the syringe. Display 58 then indicates to the operator thatcontrast reservoir 22 should be connected. Once contrast reservoir 22has been put in place, the operator is requested to depress OK switch218, at which time plunger 20 will retract at a set rate (preferablycorresponding to a flow rate of 10 ml per second) to the maximum syringevolume. If the real speed (as indicated by feedback to computer 100 fromA/D converter 116) is greater than the set speed, system 10 will stop.

Once plunger 20 is at its rearward most position, motor 104 is actuatedto move plunger 20 forward to purge all air bubbles. Pressure sensor 114provides an indication of when one-way valve 24 is closed and pressureis beginning to build up within syringe body 18. Once the purge iscompleted, the total volume injected and the number of injectionscounter is reset.

The actuation of switch 200 also allows for M1 retraction anddisengagement of plunger 20 from syringe body 18.

Purge switch 202 is a protected momentary push button switch. Whenactivated, Purge switch 202 causes plunger 20 to move forward to expelair through top port 78. The forward movement of plunger 20 is limitedand stopped when a predetermined pressure within syringe 18 is reached.This is sensed by pressure sensor 114. The purge operation which isinitiated by Purge switch 202 will expel air within syringe 20. The usermay also use Purge switch 202 to purge fluid through patient port 84 bydepressing and holding Purge switch 202 continuously on.

Aspirate switch 204 is a momentary push button switch which causescomputer 100 to activate pump motor 120 of peristaltic pump 44. Pumpmotor 120 is operated to aspirate catheter 30 at a set speed. with theaspirated fluid being collected in waste bag 52. All other motionfunctions are disengaged during aspiration. If the real speed of motor120 is greater than a set speed, computer 100 will stop motor 120.

Saline switch 206 is an alternate action switch. Pump motor 120 isactivated in response to Saline switch 206 being pushed on, and salinesolution from bag 50 is introduced into manifold 26 and catheter 30 at aset speed. If Saline switch 206 is not pushed a second time to stop theflow of saline solution within 10 seconds, computer 100 automaticallystops pump motor 120. If a time-out is reached, Saline switch 206 mustbe reset to its original state prior to initiating any further actions.

Enable OK switch 208 is a momentary push button switch. After the systemhas detected a disabling function at the end of an injection other thana limit, Enable OK switch 208 must be activated prior to activating OKswitch 218 and initiating any further function.

Injection Volume Limit keys 210 a and 210 b are pushed to eitherincrease or decrease the maximum injection volume that the system willinject during any one injection. Key 210 a causes an increase in themaximum volume value, and key 210 b causes a decrease. Once the maximuminjection volume limit has been set, if the measured volume reaches theset value, computer 100 will stop motor 104 and will not restart untilOK switch 218 has been depressed. If a large injection (i.e., greaterthan 10 ml) has been selected, OK switch 218 and Large Injection OKswitch 220 must both be reset prior to initiating the large injection.

Injection Flow Rate Limit keys 212 a and 212 b allow the physician toselect the maximum flow rate that the system can reach during any oneinjection. If the measured rate (which is determined by the feedbacksignals from tachometer 108 and potentiometer 110) reaches the setvalue, computer 100 will control motor 104 to limit the flow rate to theset value.

Injection Pressure Limit keys 214 a and 214 b allow the physician toselect the maximum pressure that the system can reach during any oneinjection. If the measured pressure, as determined by pressure sensor114, reaches the set value, computer 100 will control motor 104 to limitthe pressure to the injection pressure limit. The injection rate willalso be limited as a result.

Rise Time keys 216 a and 216 b allow the physician to select the risetime that the system will allow while changing flow rate during any oneinjection. Computer 100 controls motor 104 to limit the rise time to theset value.

In alternative embodiments, keys 210 a-210 b, 212 a-212 b, 214 a-214 b,and 216 a-216 b can be replaced by other devices for selecting numericalvalues. These include selector dials, numerical keypads, and touchscreens.

OK switch 218 is a momentary push button switch which resets functionsand hardware sensors. In response to OK switch 218 being activated,computer 100 controls display 58 to ask the operator to acknowledge thatthe correct function has been selected. Activation of OK switch 218causes the status to be set to Ready.

Injection Range switch 220 is a toggle switch. Depending on whetherswitch 220 is in the “small” or “large” position, it selects either ahigh or a low injection volume range for the next injection.

Large Injection OK switch 222 is a momentary push button switch. Whenthe large injection range has been selected by injection range switch220, the Large Injection OK button 222 must be activated to enable OKswitch 218. OK switch 218 must be activated prior to each injection. Onlarge volume injections, the user is required to verify the volumeselected by activating first Large Injection OK switch 222 and then OKswitch 218.

Stop switch 224 is a momentary push button switch. When stop switch 224is pushed, it disables all functions. Display 58 remains active.

Display panel 58 includes Set-Up display 250, Status display 252, Alertsdisplay 254, Limits display 256, total number of injections display 260,total volume injection display 262, flow rate display 264, injectionvolume display 266, injection volume limit display 268, injection ratelimit display 270, pressure, limit display 272, rise time minimumdisplay 274, large injection display 276, and real time clock display278.

Set-Up display 250 contains a series of messages which are displayed asthe operator goes through the set up procedure. The display of messagesin. set up display 250 are initiated by the actuation of set up switch200 as described previously.

Status display 252 provides a flashing indication of one of severaldifferent operating conditions. In the embodiment shown in FIG. 4, thesestatus conditions which can be displayed include “Ready”, “Set-Up”,“Injecting”, “Filling”, “Flushing”, and “Aspirating”.

Alerts display 254 and Limits display 256 notify the operator ofconditions in which system 10 has encountered a critical controlparameter and will disable operation, or has reached an upper or lowerlimit and will continue to function in a limited fashion, or has reachedan upper or lower limit and will continue to operate.

Total number of injections display 260 displays the total number ofinjections (cumulative) given for the current patient case. Thecumulative total volume injected during the current patient case isdisplayed by total volume display 262.

Displays 264 and 266 provide information on the current or lastinjection. Display 264 shows digital value of the real time flow rate tothe patient during injection. Once the injection is completed, the valuedisplayed on display 264 represents the peak flow rate reached duringthat injection. Display 266 shows the digital value of the volumeinjected during the most recent injection.

Display 268 displays the digital value of the maximum injection volumeselected by operation of switches 210 a and 210 b. Similarly, display270 shows the digital value of the maximum flow rate that the systemwill allow, as selected by switches 212 a and 212 b.

Display 272 shows the digital value of the maximum pressure that thesystem will allow to be developed in syringe 18. The pressure limit isselected by switches 214 a and 214 b.

Display 274 displays the minimum rise time that the system will allowwhile changing flow rate. The minimum rise time is selected throughswitches 216 a and 216 b.

Large injection display 276 provides a clear indication when the largeinjection scale has been selected by the operator.

Real-time clock display 278 shows the current time in hours, minutes,and seconds.

FIGS. 5A and 5B show remote control 14 which includes main housing 300,which is designed to conform to the users hand. Trigger 66 is movablewith respect to housing 300, and the position of trigger 66 generates acommand signal which is a function of trigger position. In oneembodiment, trigger 66 is linked to a potentiometer within housing 300.The command signal controls the injunction flow rate or speed. The flowrate is directly proportional to trigger position.

Reset switch 62 is a momentary push button switch whose function isidentical to that of OK switch 218. Alternatively, Reset switch 62 mayalso be labeled “OK”.

Saline switch 64 on remote control 14 is an alternate action push buttonswitch which is pushed to turn on and pushed again to turn off. Thefunction of Saline switch 62 is the same as that of Saline switch 206 onfront panel 54.

As illustrated in another embodiment of the present invention, analternative remote control 14′ in the form of a foot pedal is usedinstead of the hand held remote control 14 illustrated in FIG. 1 and inFIGS. 5A and 5B. Foot pedal remote control 14′ includes foot operatedspeed pedal or trigger 66′ for providing a command signal, as well asReset or OK switch 62′ and Saline switch 64′. Covers 310 and 312 protectswitches 62′ and 64′ so that they can only be actuated by hand and notaccidentally by foot. Foot pedal remote control 14′ is connected toconsole 12 by cable 60′, but could alternatively be connected by awireless link.

FIGS. 7A-7D and FIGS. 8A-8C illustrate the construction and operation ofone way valve 24 and manifold 26 during Contrast Fill, Air Purge andPatient Injection operation.

FIGS. 7A and 8A illustrate one way or check valve 24, manifold 26,syringe body 18, and plunger 20 during a Contrast Fill operation. Inletcheck valve of one way valve 24 includes weighted ball 350 which ispositioned at its lower seated position within valve chamber 352 inFIGS. 7A and 7B. Contrast material is being drawn into syringe body 18by the rearward movement of plunger 20. The contrast material flowsthrough passages 354 around ball 350 and into upper port 78.

Manifold 26 contains spring loaded spool valve 360, which includes spoolbody 362, shaft 364, O-rings 366, 368 and 370, bias spring 372, andretainer 374. As shown in FIG. 7A, during the Contrast Fill operation,bias spring 372 urges spool body 362 to its right-most position towardsyringe body 18. In this position, spool body 362 blocks lower port 80of syringe body 18 while connecting transducer saline port 82 to patientport 84 through diagonal passage 376. O-rings 366 and 368 on the onehand, and O-ring 370 on the other hand, are positioned on the oppositesides of diagonal passage 376 to provide a fluid seal.

FIGS. 7B and 8B illustrate the Air Purge operation. Syringe body 18 hasbeen filled with contrast fluid, but also contains trapped air. Plunger20 is driven forward to force the air out of syringe body 18 throughupper port 78 and through check valve 24. The force of the air may causea slight lifting of ball 350 in check valve 20. Ball 350, however, issufficiently heavy that the air being forced out of syringe body 18 andback toward reservoir 22 cannot lift ball 350 into its uppermost seatedposition where it would block the flow of air out of syringe body 18.

During the Air Purge operation, spool valve 360 is in the same positionas in FIG. 7A. Diagonal passage 376 connects transducer saline port 82with patient port 84. As a result pressure monitoring by pressuretransducer 38 can be performed during the Air Purge (as well as theContrast Fill) operation.

FIGS. 7C and 8C illustrate the state of manifold 26 and check valve 24at the end of the Air Purge operation and at the beginning of a PatientInject operation.

In FIG. 7C, all air has been expelled from syringe body 18. Ball 350 mayfloat on the radiographic contrast material, so that when all air hasbeen removed and the radiographic contrast material begins to flow outof syringe body 18 and through upper port 78 to valve chamber 352, ball350 is moved upwards to its upper seated position. Ball 350 blocks anycontinued upward flow of radiographic contrast material, as isillustrated in FIGS. 7C and 8C.

In the state which is illustrated in FIG. 7C, the pressure withinsyringe body 18, and specifically the pressure in lower port 80 has notyet reached a level at which the bias force of spring 372 has beenovercome. As a result, spool body 362 has not yet moved to the left anddiagonal passage 376 continues to connect transducer saline port 82 withpatient port 84.

FIG. 7D illustrates the patient inject operation. Plunger 20 is movingforward, and inlet check valve 24 is closed. The pressure at lower port80 has become sufficiently high to overcome the bias force of spring372. Spool body 362 has been driven to the left so that lower port 80 isconnected to patient port 84. At the same time spool body 362 blockstransducer/saline port 82.

By virtue of the operation of spool valve 360, the high pressuregenerated by movement of plunger 20 and syringe body 18 is directlyconnected to patient port 84, while saline port 82 and pressuretransducer 38 are protected from the high pressure. The pressure toactuate may be variable and determined after manufacture by increasingor decreasing the syringe preload.

B. Detailed Description of the Present Invention

FIG. 9 illustrates another embodiment for an injector system 400according to the invention. According to this embodiment, system 400includes a main console 401, syringe holder 410, syringe body 411,syringe plunger 412, radiographic material reservoir 413, one-way valve414, lower port 415, lower port tube 416, manifold assembly 417, patienttube 418, three-way stopcock 419, catheter 420 and transducer 430.Tubing 431 is similar to tubing 42 of the previously describedembodiments and provides for saline flush or waste removal. In addition,the previously described peristaltic pump, saline check valve, wastecheck valve, saline bag, waste bag, bag support rack, counsel and remotecontrol previously described can be used in the present embodiment.

Lower port 415 of syringe body 411 is connected to manifold assembly 417through high pressure port 432 optionally using lower port tube 416.Manifold assembly 417 includes a spring bias spool valve as describedbelow. The spring bias spool valve can be manually operated by handle435. During low pressure operation, manifold assembly 417 provides afluiditic connection from low pressure port 434 to patient port 433.During high pressure operation, manifold assembly 417 provides afluiditic connection from high pressure port 432 to patient port 433.Hence, during a patient inject operation, the pressure of injection ofthe radiographic material causes the spool valve in manifold assembly417 to change from the low pressure position to the high pressureposition such that lower port 415 is in fluid flow communication withpatient port 433.

In some embodiments, the spring bias spool valve which controls routingof fluid flow through manifold assembly 417, can be manually operated bypulling or pushing handle 435. According to the illustrated embodiment,moving handle 435 away from manifold assembly 417 changes fluid flowfrom the low pressure path (i.e., low pressure port 434 to patient port433) to the high pressure path (i.e., high pressure port 432 to patientport 433).

Patient tube 418 can be a flexible tube which connects patient port 433to catheter 420. A three-way stopcock 419 can be located at the distalend of patient tube 418. Rotatable lure lock connector 421 mates withlure connector 422 at the proximal end of catheter 420. Stopcock 419either permits or blocks flow between patient tube 418 and catheter 420,or connects medication port 423 to catheter 420. As described earlier, adevice for delivering patient medication may be connected to medicationport 423.

When catheter 420 is in place in the patient, and an injection ofradiographic contrast material is not taking place, i.e., low pressureoperation, pressure transducer 430 monitors the blood pressure throughthe column of fluid which passes through catheter 420, patient tube 418,patient port 433, manifold assembly 417, low pressure port 434, lowpressure tube 436, and, dome chamber 438. Transducer connector 440couples a first end of low pressure tube 436 to transducer 430 and lowpressure connector 441 couples a second end of low pressure tube 436 tolow pressure port. As illustrated in FIG. 9, flush tube 431 can mount totransducer 430 through flush tube connector 442. In some embodiments,system 400 can also include a transducer, holder 600 (discussed below)for adjustable positioning of transducer 430. When a peristaltic pump,discussed earlier, is operating to supply saline solution through flushtube 431, the solution is supplied through manifold assembly 417 topatient port 433 and then through patient tube 418 to catheter 420. Itwill be appreciated that aspiration applied at low pressure port 434 candraw blood from the patient through patient tube 418, manifold assembly417, low pressure port 34 and into flush tube 431.

In the present embodiment, preferably, syringe body 411, manifoldassembly 417, patient tube 418, catheter 420, stopcock 423, low pressuretube 436, transducer dome chamber 438, flush tube 431 and previouslydescribed check valves, fluid containers and waste containers are alldisposable items. They should be installed in system 400 each time a newprocedure is to be performed with a new patient. Once system 400 is setup with all the disposable items installed, the operator enters into theconsole 401 of system 400, the limiting safety parameters that willapply to the patient injection of radiographic contrast material.

FIGS. 10-18 illustrate preferred embodiments of a manifold assembly 417.FIG. 10 is a side view of one embodiment of the shell (body) 450 ofmanifold assembly 417; FIG. 11 is a top view of manifold shell 450; FIG.12 is a bottom view of manifold shell 450; and FIG. 13 is a longitudinalcross section view of manifold assembly 417. These figures allillustrate high pressure port 432, patient port 433 and low pressureport 434.

FIG. 13 illustrates that manifold handle 435 has a shaft 456 that passesthrough opening 452 of manifold cap 453 . Manifold cap 453 has threads454 for securing cap 453 to first end 491 of manifold shell 450 throughmanifold shell threads 451. In the illustrated embodiment, cap 453includes a hollow protuberance 455 through which handle shaft 456 passesinto manifold 450. Manifold plunger assembly 490 includes, manifoldshaft 458, manifold wiper 460, O-ring 461 and valve sensor trigger 462.Protuberance 455 of manifold cap 453 stops travel of manifold plungerassembly 490 to the left (relative to the orientation of FIG. 13) duringhigh pressure operation. Spring 463 is mounted over handle shaft 456between manifold cap 453 and valve sensor trigger 462 to maintain afluiditic connection between low pressure port 434 and patient port 433.

Within manifold assembly 417, handle shaft 456 is rigidly fixed to afirst end 457 of manifold shaft 458 using, for example, threads.Manifold wiper 460 is mounted at the second end 459 of manifold shaft458. In the illustrated embodiment, manifold shaft 458 has a hollow corethat is open at first end 457 and second end 459. The hollow coreprovides for release of air that would otherwise be trapped inside thehollow region of manifold wiper 460 during assembly. In the illustratedembodiment, wiper 460 includes a thickened tip 497 which providesreinforcement of the wall of wiper 460 to reduce the chance of ruptureof wiper 497 into the hollow core of manifold shaft 458. Preferably,manifold wiper 460 is manufactured from an elastomeric thermosetmaterial, for example, ethylene propylene diene monomer (EPDM) silicon,nitrile, polyisoprene, etc. The resistance to compression set of thethermoset material provides for maintaining a fluid tight seal betweenthe outer perimeter of manifold wiper 460 and the inner surface 464 ofmanifold shell 450.

A valve sensor trigger 462 is mounted at the first end 457 of manifoldshaft 458. The position of the valve sensor trigger 462 is detected bythe valve state sensor 425 (FIG. 9) to indicate the state of thefluiditic connections within manifold assembly 417. In one embodiment,in the valve state sensor trigger 462 can be manufactured from stainlesssteel for use with an inductive type valve state sensor 425.

FIG. 13A illustrates a longitudinal cross section view of the second end492 of manifold shell 450 of FIG. 13. As illustrated in FIG. 13A, theinner surface 464 of shell 450 near high pressure port 432 is coneshaped 493. This cone shaped end 493 provides a gradual transition fromhigh pressure port 432 to inner surface 464 which can facilitate removalof trapped air at this junction during initial flushing of the system byminimizing adverse turbulent flow. In addition, the cone shaped end caneliminate regions of fluid stagnation during injection. In addition, theexternal configuration of the cone tip protrudes slightly and is wedgeshaped to form an annular ring 494 for an air tight pressure fit withthe inner surface 495 of lumen 496 of low port tube 416.

Referring to FIGS. 10-17, the structure of manifold shell 450 at thejunction between the inner surface 464 of manifold shell 450 and thefluid channel 466 of patient port 433 and the fluid channel 467 of lowpressure port 434 will be described.

FIGS. 14A-C are longitudinal cross section views which illustrate theinteraction of an elastomeric manifold wiper 460 a and the inner surface464 a of a manifold shell 450 a as the wiper 460 a moves from its lowpressure position (FIG. 14A) to its high pressure position (FIG. 14C. Asillustrated in FIG. 14B as wiper 460 a moves within the inner surface464 a of manifold shell 450 a past fluid channel 466 a of patient port433 a, the elastomeric material of wiper 460 a tends to “extrude”(illustrated as 465) into the fluid flow channel 466 a of patient port433 a. The same event can occur as wiper 460 a passes over fluid flowchannel 467 a of low pressure port 434 a (FIG. 14C). A potential problemwith extrusion of wiper 460 a into fluid flow channels, 466 a or 467 a,is that the extruded portion 465 of manifold wiper 460 a can preventproper functioning of manifold assembly 417 by causing plunger assembly490 to stick in a position wherein wiper 460 blocks fluid channels 466 aor 467 a. In addition, the extruded portion 465 can be broken or“nibbled” off during passage of wiper 460 a past fluid channels 466 a or467 a. In a preferred embodiment, manifold assembly 417 is constructedto reduce the amount of extrusion and reduce the likelihood of stickingor nibbling of manifold wiper 460 as it moves past fluid channels 466and 467.

FIG. 11 is a top view of manifold shell 450 looking down into fluid flowchannel 466 of patient port 433. FIG. 15 is a transverse cross sectionview through line 15 of FIG. 11. FIG. 12 is a bottom end view ofmanifold shell 450 looking into fluid channel 467 of low pressure port434. FIG. 16 is a transverse cross section view through line 16-16 ofthe low pressure port of FIG. 12. Referring to patient port 433 in FIGS.11 and 15, at the location where fluid channel 466 communicates with theinner surface 464 of manifold shell 450, the fluid channel 466 isbifurcated by a “fillet” 468 to form a multipartate opening. Asillustrated best in FIG. 15, fillet 468 permits fluid flow throughelongate openings 469 a and 469 b of shell 450 into fluid channel 466but also constrains expansion of manifold wiper 460 to reduce the amountof extrusion into fluid channel 466. Preferably, fillet 468 reduces thelikelihood of extrusion of manifold wiper 460 into fluid channel 466,but does not cause an increase in cavitation or an appreciable increasein resistance to the flow of fluid passing into fluid channel 466. Itwill be appreciated that openings 469 a and 469 b are not limited to anyparticular shape as a result of the fillet. Moreover, while FIGS. 11 and15 show a single fillet creating two openings, additional filletsforming more than two openings are envisioned within the scope of theinvention. In the illustrated embodiment, the opening is bipartate andthe longitudinal dimension of the fillet is oriented parallel to thelongitudinal dimension of the manifold shell 450. Also, in oneembodiment, the fillet is about 0.030 inch wide, the longitudinaldimension of openings 469 a and 469 b is about 0.080 inch and the widthof openings 469 a and 469 b is about 0.030 inch.

Referring now to FIGS. 12 and 16, for the reasons discussed above, asimilar fillet 470 can be present in fluid flow channel 467 of lowpressure port 434, bifurcating channel 467 into openings 471 a and 471b.

FIG. 17 diagrammatically illustrates a temporal position of manifoldwiper 460 a at a position after which the pressure at high pressure port432 a has become sufficient to overcome: (1) the bias force of spring463 (FIG. 13); (2) the friction force between manifold wiper 460 a andmanifold inner surface 464 a; (3) the pressure induced friction forcebetween seal ring 460 b and manifold inner surface 464 a. In theillustration, manifold wiper 460 a has not moved completely to the leftto the fully open high pressure position. Just after seal ring 460 c hasblocked the fluid connection between patient port 433 a and low pressureport 434 a, the pressurized fluid entering high pressure port 432 a canflow up fluid channel 466 a, at arrow 472, which reduces the pressure athigh pressure port 432 a because there is, as yet, little flowresistance or pressure build up in fluid channel 466 a.

This reduction in pressure simultaneously reduces the pressure inducedforce on the seal face 460 d and pressure induced friction force betweenseal ring 460 b and manifold inner surface 464 a. Without being limitedto a single theory, it is believed that as the forces pushing andholding the plunger assembly 490 to the left are simultaneously reduced,the force of spring 463 must also decline due to the laws of physics.Thus, spring 463 must expand, which pushes plunger assembly 490 to theright. Once manifold wiper 460 a moves far enough to the right to sealoff the fluid outflow through fluid flow channel 466 a, the pressure athigh pressure port 432 a will increase again to overcome the bias forceof spring 463 allowing wiper 460 a to move enough to the left to allowfluid to once again rush out at arrow 472. The repeated occurrence ofthe movement of wiper 460 a back and forth at the point where fluid isjust beginning to move up fluid channel 466 a at arrow 472 results in anoscillation of the plunger. This oscillation can produce a pulsation inthe fluid flow which causes uncontrolled variable flow rates.

Referring to FIGS. 11, 13 and 18, in a preferred embodiment of theinvention, manifold assembly 417 is constructed, in part, to reduce oreliminate the occurrence of this oscillation. FIG. 18 is a transversesectional view taken at line 18-18 of FIG. 11. Referring to FIGS. 11 and18, within patient port 433, there is located an outer oscillationreduction port 473. The port 473 leads into an oscillation reductionchannel 474 that extends from patient port 433, through manifold shell450 to communicate with the inner surface 464 of manifold shell 450 atinner oscillation reduction port 475 (FIGS. 13 and 18). Referring toFIG. 13, during use, as the pressure at high pressure port 432 becomessufficiently high to overcome the previously described counter forces,manifold wiper 460 moves to the left. As wiper 460 moves sufficiently tothe left to expose inner port 475 of oscillation reduction channel 474,fluid is forced up oscillation reduction channel 474. The resistance tofluid flow from the combination of inner port 475 and oscillationreduction channel 474 is sufficient to maintain the pressure within theinner surface 464 of manifold assembly 417 to prevent oscillation. Thismaintained pressure also maintains the pressure induced force on sealface 460 d. As a result, plunger assembly 490 is moved fully to the leftwithout oscillation. Thus, oscillation ports 473 and 475 and oscillationchannel 474 maintain the force balance between the biasing spring 463and the pressure induced force of the fluid on wiper 460.

Referring to FIGS. 19 and 19A, in some embodiments, the elastomericmaterial of manifold wiper 460 can be configured to form a plurality ofridges, 485 a, 485 b and 485 c. These ridges contact inner surface 464of manifold shell 450. In one aspect, the intervening valleys 486 a and486 b between ridges 485 a-485 c, help reduce the amount of frictionbetween the elastormeric surface of wiper 460 and inner surface 464while ridges 485 a and 485 c maintain a fluid tight seal. In theillustrated embodiment, ridge 485 b acts to eliminate the presence ofair between ridges 485 a and 485 c. As seen in the cross section view ofFIG. 19A, the inner surface 498 of wiper 460 includes circumferentialprotrusions 499 a and 499 b. The pressure of these protrusions againstmanifold shaft 458 causes formation of ridges 485 a and 485 c. Ridge 485b is formed by the presence of shim 500 on manifold shaft 458. It willbe appreciated that ridge 485 b could be configured to create a greaterfriction force against outer surface 464 by placement of acircurmferential protrusion similar to protrusions 499 a and 499 b.

Referring to FIGS. 19 and 19A, it is believed that the area withinvalleys 486 a and 486 b can trap air which, when wiper 460 moves pastfluid flow channel 466, could be forced into patient port 433, outpatient tubing 418 and ultimately into the patient. The ill effects ofair entering the patient's vascular system are well known. Hence, toreduce the chance of air entering the patient, manifold shell 450 caninclude projections 487 a and 487 b that substantially fill the valleys486 a and 486 b between ridges 485 a-485 c when manifold wiper 460 is inthe low pressure position, i.e., closest to high pressure port 432. Asillustrated in FIG. 19A, the interdigitation of ridges 485 a-c withprotuberances 487 a-b. reduces dead air space and the air present invalleys 486 a-486 b thus reducing the chance for air to move intopatient port 433 as wiper 460 is moved from the low pressure position.

FIG. 20, illustrates two different embodiments of temperature controldevice 555 for the fluid in reservoir 413 (22). The temperature controldevice 555 provides for heating or cooling of the injection materialprior to passing into syringe 411. In one embodiment, the temperaturecontrol device 555 can be a jacket, 556, that sufficiently coversreservoir bottle 413 to effect the temperature of the material in thereservoir. In an alternative embodiment, the temperature control devicecan be a tubular heating element or heat exchanger 557 that warms thecontrast material as it passes through the tubing 557 before enteringsyringe 411.

FIGS. 21-25 show a preferred embodiment of a remote control device 550which includes a main housing 501, which is designed to conform to theuser's hand. Trigger 502 is moveable with respect to housing 501, andthe position of trigger 502 generates a command signal which is afunction of trigger position. The flow rate of contrast material duringthe patient inject operation is directly proportional to triggerposition.

FIG. 21 is a perspective view of remote control 550. In use, remotecontrol 550 is preferably held in the user's hand such that theoperation buttons, for example, 503 and 504, on face panel 505, can bereadily actuated by the user's thumb. Trigger 502 can be operated bypulling trigger 502 toward housing 501 with one or more of the user'sfingers. Referring to the orientation of remote control 550 in thefigures, it will be appreciated that there is an upper end 506 and alower end 507. Referring to the top view of FIG. 25, housing 500includes a slot 508 that guides the lateral travel of trigger 502through guide pin 509. Also, as trigger 502 is pulled, the forward andbackward travel of trigger 502 is limited. Backwall 510 of slot 508limits backward travel and forward wall 511 of slot 508 limits forwardtravel. As illustrated in FIG. 25, slot 508 can be in the form of an “L”512. The “L” configuration of slot 508 provides for guide pin 509 torest within the short arm of the L when not in use, and requires lateralmovement of trigger 502 to dislodge guide pin 509 from the short armbefore trigger 502 can be pulled towards housing 501. This feature ofremote control 500 helps prevent against accidental patient injectionwithout an affirmative lateral movement of trigger 502 by the operator.

The bottom end 507 of trigger 502 can mount with housing 501 through apivot arrangement, for example, a spring hinge or a flexible materialwhich provides for repeated pulling of handle 502 towards housing 501and return to the forward position when the operator releases trigger502.

A maximum and minimum fluid discharge rate is set by the operator forthe remote control prior to operation. The rate of fluid discharge canbe varied by the operator and is directly proportional to the triggerposition. That is, in one embodiment, the farther back that trigger 502is pulled toward housing 501, the greater the fluid discharge rate up tothe preset maximum.

Referring to FIGS. 21 and 24, face panel 505 can include an indicatorlight 520 which illuminates when the system is armed and ready for use.Other control functions can be operated at the face panel. For example,in one embodiment, operation button 504 provides for a saline flushthrough the low pressure side of the system, and operation button 503provides a “spritz” function through the high pressure side of thesystem. It will be appreciated that other functions can be remotelycontrolled through operation buttons installed at the face panel 505.

As stated above, in one embodiment, face panel 505 includes an operationbutton 503 providing a “spritz” function. According to this embodiment,activation of operation button 503 will cause injection of apredetermined volume of contrast media at the operator's discretion.This function may be particularly useful when determining position ofcatheter in a heart, peripheral vessel or other anatomical location inthe body. In one embodiment, activation of the spritz button will injecta volume of contrast media that is a percentage of the preset injectionvolume. For example, activation of a spritz button could inject 10% ofthe injection during small hunting procedures.

In some embodiments, an angiographic injector system according to theinvention can include a transducer holder 600 for selective positioningof transducer 430 relative to the patient's heart line. As illustratedin FIGS. 9 and 26, transducer holder 600 includes a mounting shaft 601,for mounting transducer holder 600 to console 401, and adjustment shaft602 for slidable adjustment of transducer 430 in transducer carrier 603.Movement of transducer carrier 603 along adjustment shaft 602 is limitedat a first end by mounting shaft 601 and at a second end by adjustmentshaft cap 604. Depressing adjustment sleeve 606 allows transducercarrier 603 to be moved freely along adjustment shaft 602.

In the illustrated embodiment, transducer carrier 603 includes twosites, 613 and 614 for mounting transducer 430. These sites areconfigured to conform to the shape of transducer 430 or transducer dome438 for a snug fit regardless of the rotational orientation ofadjustment shaft 602.

Referring to FIG. 26, spring 605 and adjustment sleeve 606 are locatedwithin chamber 608 of carrier 603. Adjustment sleeve 606 includes achannel 607 which fits around adjustment shaft 602. Adjustment shaft 602also passes through channel 610 of transducer carrier 603. In use, whenadjustment sleeve 606 is depressed towards end 611 of transducer carrier603 such that channel 607 and channel 610 are in axial alignment,transducer carrier 603 can be slidably moved along adjustment shaft 602.Upon release of pressure on adjustment sleeve 606 channel 607 ofadjustment sleeve 606 is biased out of axial alignment with channel 610creating a friction force which holds transducer carrier 603 inposition.

In addition to slidable adjustment of carrier 603 along adjustment shaft602, shaft 602 can be rotated 360° around an axis 612 through mountingshaft 601. Thus, between rotational adjustment and slidable adjustment,transducer 430, mounted in transducer carrier 603, can be positioned atthe optimum location for monitoring a patient's blood pressure.

In one preferred embodiment, when the volume of contrast material insyringe 411 is less than the injection volume as determined by themicroprocessor, the injector system will prevent subsequent injectionoperations or automatically refill syringe 411. In auto mode or manualmode, syringe 411 can be refilled maximally or to some lesser volumeentered by the operator at console 401. In automatic mode, subsequent tocompletion of an injection, computer 100 compares the volume of contrastmaterial remaining in syringe 411 with the injection volume preset inthe computer by the operator. If the preset injection volume is greaterthan the volume of contrast material available in syringe 411, computer100 prevents subsequent patient injection operations. Provided contrastreservoir 413 (or 22) is in place, computer 100 can energize the motordrive circuitry to automatically retract plunger 412 at a set rate,preferably corresponding to a flow rate of about 3 ml per second, toload syringe 411 with contrast material to maximum or other presetvolume. Once syringe 411 is filled as indicated by the reverse limitfeedback signal from sensor 164, motor 104 moves plunger 412 forward topurge air from the syringe out one-way valve 414 at a rate of about 3 mlper second.

It has also been discovered that by using multiple speeds for retractingof plunger 412 during syringe refill, an air forming bubble withinsyringe 411 can be reduced more readily. For example, assume a situationwhere syringe 411 is to be maximally filled. According to this example,the computer controlled retraction of plunger 412 occurs slowly at arate of about 2 ml per second until filled with about 40 ml of mediaThis slower rate facilitates a forming air bubble to break free from thesurface of plunger 412 at the meniscus. Subsequently, a faster rate ofabout 3 ml per second is used to complete the filling procedure and thebubble released from plunger 412 will tend to float away from theplunger toward one-way valve 414. In addition, angulation of syringe 411at about 10-20°, preferably about 15° from horizontal facilitatesrelease or movement of an air bubble to one-way valve 14.

In conclusion, the injector system of the present invention providesinteractive control of the delivery of radiographic contrast material toa catheter through a user actuated proportional control. The severalembodiments disclosed herein enhance the safety and efficiency of theinjector system as well as providing for the user to adjust theparameters for injection of contrast material interactively as neededand as the patient's condition changes.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. For example, syringe holder 16 and 410 maytake other forms, such as an end loaded cylinder. Similarly, manifolds26 and 417 can take other configurations and can incorporate, forexample, a part of syringe ports 78 and 80.

What is claimed is:
 1. A device for injecting angiographic fluid into apatient comprising: an actuator assembly; a syringe, said syringe beingengageable with said actuator assembly; said syringe having a fluidinlet port; a valve associated with said fluid inlet port, said valvebeing automatically actuatable into an open position as a response torearward movement of said actuator assembly relative to said syringe andautomatically actuatable to purge air from said syringe during forwardmovement of said actuator assembly; a reservoir of angiographic fluid,said reservoir being positioned relative to said syringe such that saidreservoir is in continuous communication with said fluid inlet port ofsaid syringe at least during the performance of an injection procedureon a patient; and, said reservoir sized to contain a volume of fluidthat exceeds a maximum capacity of said syringe.
 2. A device accordingto claim 1, wherein said syringe contains an outlet port through whichangiographic fluid is expelled from said syringe during said injectionprocedure.
 3. A device according to claim 1, wherein said injectionprocedure includes the injection of a quantity of angiographic fluidthat is greater than the maximum capacity of said syringe and is lessthan or equal to the volume of fluid contained in said reservoir priorto the initiation of said injection procedure.
 4. A device according toclaim 1, wherein a flow control valve is interposed between saidreservoir and said syringe, said flow control valve having an openposition and a closed position.
 5. A device according to claim 4,wherein said flow control valve is disposed in said fluid inlet port ofsaid syringe.
 6. A device according to claim 4, wherein said flowcontrol valve is a ball valve.
 7. A device according to claim 4, whereinsaid syringe includes a plunger axially movable within said syringeaccording to movement of said actuator assembly.
 8. A device accordingto claim 7, wherein said flow control valve is disposed between saidreservoir and said syringe such that said valve assumes its openposition upon rearward movement of said plunger.
 9. A device accordingto claim 7, wherein said syringe includes an outlet port through whichangiographic fluid is expelled from said syringe.
 10. A device accordingto claim 9, further including a conduit extending from said outlet portto said patient.
 11. A device according to claim 10, wherein saidconduit includes an outflow control valve having at least a closedposition.
 12. A device according to claim 11, wherein said outflowcontrol valve is in said closed position upon rearward movement of saidplunger.
 13. A device according to claim 1, wherein said angiographicfluid is selected from the group of fluid consisting of fluid forperforming a radiologic injection, fluid for performing a magneticresonance imaging injection; fluid for performing a cardiologicinjection.
 14. A method of injecting angiographic fluid into a patientcomprising: providing an actuator assembly; providing a syringeengageable with said actuator assembly; providing a valve associatedwith a fluid inlet port of said syringe; providing a reservoir ofangiographic fluid; placing said reservoir into communication with saidsyringe; automatically opening said valve in response to a rearwardmovement of said actuator assembly relative to said syringe;automatically acutuating said valve to purge air from said syringeduring forward movement of said actuator assembly; injecting an amountof angiographic fluid into a patient wherein said amount exceeds amaximum capacity of said syringe but is less than or equal to the volumeof fluid present in said reservoir prior to the injecting; andmaintaining constant communication between said reservoir and saidsyringe throughout the injecting.
 15. A method as set forth in claim 14,wherein said act of injecting includes moving a plunger in said syringein a forward direction to expel said angiographic fluid from saidsyringe.
 16. A method as set forth in claim 15, wherein said act ofinjecting includes at least partially refilling said syringe after anamount of angiographic fluid has been expelled from said syringe.
 17. Amethod as set forth in claim 16, wherein said partial refilling of saidsyringe occurs after said syringe has been substantially emptied of saidangiographic fluid.
 18. A method as set forth in claim 16, wherein saidact of at least partially refilling includes moving said plunger in arearward direction and thereby drawing fluid into said syringe from saidreservoir.
 19. A method as set forth in claim 14, wherein prior to saidact of injecting, said syringe is filled with angiographic fluid.
 20. Amethod as set forth in claim 19, wherein said act of filling saidsyringe includes moving a plunger internal to said syringe in a rearwarddirection thereby drawing angiographic fluid into said syringe from saidreservoir.
 21. A method as set forth in claim 20, wherein saidangiographic fluid is drawn into said syringe from said reservoirthrough a flow control valve.
 22. A method as set forth in claim 20,wherein said act of injecting includes moving a plunger in said syringein a forward direction to expel said angiographic fluid from saidsyringe.
 23. A method as set forth in claim 22, wherein said act ofinjecting includes at least partially refilling said syringe after anamount of angiographic fluid has been expelled from said syringe.
 24. Amethod as set forth in claim 23, wherein said partial refilling of saidsyringe occurs after said syringe has been substantially emptied of saidangiographic fluid.
 25. A method as set forth in claim 23, wherein saidact of at least partially refilling includes moving said plunger in arearward direction and thereby drawing fluid into said syringe from saidreservoir.